The differences between adaptive and random genetic changes during the evolution of E. coli

After Twenty-one years and 40,000 generations of bacteria later, Richard Lenski, professor of microbial ecology at Michigan State University, reveals new details about the differences between adaptive and random genetic changes during evolution in E. coli.

"Sequencing genomes of various generations of the bacteria, which had been frozen periodically over the years, Lenski and his team found that adaptive and random genomic changes don't necessarily follow the same patterns."

The results have lead the authors to state that calculating rates and types of evolutionary change may be even more difficult to do without a rich data set.

"The fluid and complex coupling observed between the rates of genomic evolution and adaptation even in this simplistic system cautions against categorical interpretations about rates of genomic evolution in nature without specific knowledge of molecular and population-genetic processes."